Circadian rhythm is a change of a roughly 24-hour cycle in vital activities (e.g., food intake, body activities, sleep, awakening of animals), which is driven by a circadian clock. When the circadian rhythm of human bodies is disturbed, it will lead to changes in the body's biological clock, decrease in sleep quality, irregularity of hormonal secretion, and decrease in the ability to act. Thus, work efficiency will be reduced, probability of accidents will increase, and many diseases (e.g., depressive disorder) may be induced.
Currently, Diazepam and Lorazepam are common drugs used in clinic for regulating circadian rhythm to treat related diseases such as insomnia and depressive disorder. However, patients are prone to addiction after using the aforementioned drugs and may have side effects, such as hypersomnia, nausea, headache, vomiting, gastrointestinal discomfort, memory impairment, rebound insomnia, unconsciousness, ataxia, dyspnea, and/or somnambulism. Therefore, there is necessity and urgency for continuously developing a drug or method for regulating circadian rhythm effectively without causing addictions and side effects.
It was revealed by researches that a human body's circadian rhythm and sleep cycle are regulated by the expressions of genes including CLOCK (circadian locomotor output cycles kaput), ARNTL (aryl hydrocarbon receptor nuclear translocator like), and PER2 (period circadian clock 2). Thus, if the expressions of CLOCK gene, ARNTL gene, and PER2 gene could be increased, the circadian rhythm will be effectively regulated which is beneficial to adjust a biological clock, improve sleep quality and facilitate sleep.
Inventors of the present invention found that Momordica charantia extract is effective in regulating the expressions of genes, i.e., CLOCK, ARNTL, and PER2 genes, and thus, can be used for adjusting the biological clock, improving sleep quality, and/or facilitating sleep, as well as can be used for treating or preventing diseases related to the aforementioned genes, and/or regulating physiological functions related to the aforementioned genes. Preferably, the Momordica charantia extract is an extract of a roasted fruit of Momordica charantia. 